In order to assess safety in human of such chemicals as pharmaceuticals, pesticides, cosmetics and industrial products, many toxicity tests using non-human animals are typically conducted. Toxicities to reproductive ability and to development of unborn child and newborn are included in toxicity collectively referred to as reproductive and developmental toxicity, and it is required to conduct tests for these toxicities for production and distribution of pharmaceuticals, pesticides and other chemicals. As an example of developmental toxicity test, referred to as a teratogenicity test is a test in which a chemical is administered to a non-human mammal during its pregnancy followed by examining the fetus of the mammal for presence and extent of morphological defect, and in general, developmental toxicity of a chemical is evaluated by administering the chemical for a certain period to a pregnant female of a non-human animal such as rat, mouse, rabbit or simian and closely observing the external form, internal organs and skeleton of the fetus of the animal.
However, the developmental toxicity test using non-human animals requires a lot of time and cost, such as those for breeding of animals. Therefore, developed as simplified methods for embryotoxicity testing using mammalian cells or tissue have been a testing method using mouse embryonic stem cells (hereinafter, sometimes referred to as ES cells) (EST: Embryonic Stem cell Test) (H. Spielmann, I. Pohl, B. Doring, M. Liebsch, F. Moldenhauer, In vitro toxicology, 10(1), p 119-127, 1997, E. Genschow, H. Spielmann, G. Scholz, I. Pohl, A. Seiler, N. Clemann, S. Bremer, K. Becker, ATLA 32, p 209-244, 2004), micromass culture using rat embryo limb buds and whole-embryo culture using an early rat embryo (E. Genschow, H. Spielmann, G. Scholz, A. Seiler, N. Brown, A. Piersma, M. Brady, N. Clemann, H. Huuskonen, F. Paillard, S. Bremer, K. Becker, ATLA 30, p 151-176, 2002), and so on, however, reliability on accuracy has not been established in any method.